Thus, Greek entered its classical era with seven letters and two digraphs – <α, ε, ι, ο, υ, η, ω, ει, ου> – for twelve vowel sounds.
At the same time, phonetic changes that led to a greater number of different phonemes in the spoken language, when Proto-Norse evolved into Old Norse.
Languages with a long literary history have a tendency to freeze spelling at an early stage, leaving subsequent pronunciation shifts unrecorded.
By contrast, some writing systems have been periodically respelled in accordance with changed pronunciation, such as Dutch, Portuguese, Spanish, Irish, and Japanese hiragana.
Moreover, the defective nature of the script has its benefits: the stable shape of the root words, despite grammatical inflection, results in quicker word recognition and therefore faster reading speeds; and the lack of short vowels, the sounds which vary the most between Arabic dialects, makes texts more widely accessible to a diverse audience.
[8] Non-native speakers learning Arabic or Persian, however, do suffer difficulties in acquiring correct pronunciation from undermarked pedagogical material.
Further, in mašq and those styles of kufic writing which lack consonant pointing, the ambiguities are more serious, for here different roots are written the same.
[6]: 758 However, some adaptions of the Arabic alphabet do unambiguously and compulsorily mark all vowels: among them, those for Bosnian, Kashmiri,[6]: 753 Kyrgyz, Mandarin, Sorani, and Uyghur.
[6]: 748 When a defective script is written with diacritics or other conventions to indicate all phonemic distinctions, the result is called plene writing.